This known circuit and other known circuits for power factor correction (see e.g. the cited document, U.S. Pat. No. 4,808,887, No. 5,008,597, No. 5,371,440, No. 5,521,467, No. 5,789,871, No. 5,914,572, No. 6,057,652, No. 6,091,206, DE-A-3 142 613, WO 97/22231, WO 99/25159, JP-A-10-214 695, JP-A-2000-012 257) are currently used, for example, in modern electronic ballasts, which convert the electrical power from the available mains voltages, usually alternating voltages, in such a way that each of the connected loads, mainly lamps, can be operated in their optimum voltage, current and frequency range. With respect to the mains system, the electronic ballasts are meant to exhibit an electrical response corresponding as closely as possible to a resistance in order to avoid distortions in the mains current and the mains voltage.
The known circuits for power factor correction work at frequencies of 20 to 100 kHz. The frequency is the determining factor for the size of the inductors and capacitors that are required, which are by far the largest components of such circuits.
The invention is based on the problem of providing a circuit for power factor correction that enables miniaturization of this circuit.